diff --git a/source/RobotAPI/libraries/armem/core/base/EntityInstanceBase.h b/source/RobotAPI/libraries/armem/core/base/EntityInstanceBase.h
index 26806524c61fe00b14ba8cab2c9cdf795f89b91d..c756b9959a6d43657c331181de1643c8df06f71d 100644
--- a/source/RobotAPI/libraries/armem/core/base/EntityInstanceBase.h
+++ b/source/RobotAPI/libraries/armem/core/base/EntityInstanceBase.h
@@ -11,9 +11,9 @@ namespace armarx::armem::base
 
     struct Metadata
     {
-        virtual void access() const = 0;
-
         virtual ~Metadata() = default;
+
+        virtual void access() const = 0;
     };
 
     /**
@@ -21,12 +21,20 @@ namespace armarx::armem::base
      */
     struct NoData : public Metadata
     {
-        void access() const final {}
-
         virtual ~NoData() = default;
 
-        bool operator==(const NoData& other) { return true; }
-        bool operator!=(const NoData& other) { return false;}
+        void access() const final
+        {
+        }
+
+        bool operator==(const NoData& other)
+        {
+            return true;
+        }
+        bool operator!=(const NoData& other)
+        {
+            return false;
+        }
     };
 
 
@@ -35,8 +43,16 @@ namespace armarx::armem::base
      */
     struct EntityInstanceMetadata : public Metadata
     {
-        /// Time when this value was created.
+        ///
+        /**
+         * @brief Time this instance refers to.
+         *
+         * For example, the physical time point when an image was captured.
+         * If the image is processed, the result should have the same
+         * referencedTime as the image.
+         */
         Time referencedTime = Time::Invalid();
+
         /// Time when this value was sent to the memory.
         Time sentTime = Time::Invalid();
         /// Time when this value has arrived at the memory.
@@ -51,10 +67,10 @@ namespace armarx::armem::base
         /// A counter how often the instance has been accessed
         mutable unsigned long accessed = 0;
 
-        void access() const final;
-
         virtual ~EntityInstanceMetadata() = default;
 
+        void access() const final;
+
         bool operator==(const EntityInstanceMetadata& other) const;
         inline bool operator!=(const EntityInstanceMetadata& other) const
         {